Weblogic containers output images through JSP pages without garbled characters, but Tomcat works normally.

These days, I have been dizzy with a problem. In my project, I want to implement such a function to display a three-dimensional vector chart in the report (which is actually not so amazing ), therefore, you need to write a jsp page to output the image.

It was already successfully debugged under tomcat, but garbled characters appeared when the on-site debugging function was reached. As a result, I tried my best to solve the problem. Finally, under the guidance of the company, we finally solved the problem.

The file processing rules of weblogic are different from those of tomcat, as shown in the following code:

 

<%@page import="java.io.OutputStream"%> <%@page import="javax.imageio.ImageIO"%> <%@page import="java.awt.Color"%> <%@page import="java.awt.Font"%> <%@page import="java.awt.Graphics"%> <%@page import="java.awt.image.BufferedImage"%> <%@page import="java.io.BufferedOutputStream"%> <%@page import="java.io.FileOutputStream"%> <%@page import="java.util.Date"%> <%@page import="java.util.Random"%> <%@page import="com.sun.image.codec.jpeg.JPEGCodec"%> <%@page import="com.sun.image.codec.jpeg.JPEGImageEncoder"%> <%@page import="java.io.OutputStream"%><%@page import="javax.imageio.ImageIO"%><%@page import="java.awt.Color"%><%@page import="java.awt.Font"%><%@page import="java.awt.Graphics"%><%@page import="java.awt.image.BufferedImage"%><%@page import="java.io.BufferedOutputStream"%><%@page import="java.io.FileOutputStream"%><%@page import="java.util.Date"%><%@page import="java.util.Random"%><%@page import="com.sun.image.codec.jpeg.JPEGCodec"%><%@page import="com.sun.image.codec.jpeg.JPEGImageEncoder"%>

For tomcat containers, tomcat will automatically process
 

。[<%@page import="java.io.OutputStream"%><%@page import="javax.imageio.ImageIO"%> <%@page import="java.io.OutputStream"%><%@page import="javax.imageio.ImageIO"%>

That is to say, for jsp files, tomcat automatically removes line breaks and space characters.

However, weblogic does not have such a processing rule. Instead

 

<%@page import="java.io.OutputStream"%> <%@page import="javax.imageio.ImageIO"%> <%@page import="java.io.OutputStream"%><%@page import="javax.imageio.ImageIO"%>

Such code is output with a carriage return. This symbol is naturally combined with the stream of the output image below. Some line breaks are added at the beginning of the image stream, which naturally cannot be displayed normally.

But garbled characters appear.

The key to solving this problem is to check whether there are redundant carriage returns and spaces in the jsp file. If yes, remove them, then, change the declaration at the beginning of the file to the following form to avoid outputting redundant carriage returns.

The correct jsp page should be like this, for example:

<% @ Page import = "java. io. outputStream "%> <% @ page import =" javax. imageio. imageIO "%> <% @ page import =" java. awt. color "%> <% @ page import =" java. awt. font "%> <% @ page import =" java. awt. graphics "%> <% @ page import =" java. awt. image. bufferedImage "%> <% @ page import =" java. io. bufferedOutputStream "%> <% @ page import =" java. io. fileOutputStream "%> <% @ page import =" java. util. date "%> <% @ page import =" java. util. random "%> <% @ pag E import = "com.sun.image.codec.jpeg. sharecodec" %> <% @ page import = "com.sun.image.codec.jpeg. shareimageencoder" %> <%! /*** Add text **/private void addText (Graphics graphics, String [] zbm, int I, Integer [] bd, int wz ){/*... Privacy... */}%> <% Try {String zfx = request. getParameter ("zfx"); String i1 = request. getParameter ("uaia"); String i2 = request. getParameter ("ubib"); String i3 = request. getParameter ("ucic"); Double uaia = Double. valueOf (i1); Double ubib = Double. valueOf (i2); Double ucic = Double. valueOf (i3); int imageWidth = 224; // The image Width int imageHeight = 175; // The image Height BufferedImage image = new BufferedImage (imageWidth, imageHeight, BufferedImage. TYPE_INT_RGB); Graphics graphics = image. getGraphics (); graphics. setColor (Color. white); graphics. fillRect (0, 0, imageWidth, imageHeight); graphics. setColor (Color. black);/* privacy */graphics. dispose (); OutputStream outs = response. getOutputStream (); ImageIO. write (image, "jpeg", outs);} catch (Exception e) {e. printStackTrace () ;}%>